JP2019079718A - Overhead distribution line - Google Patents

Abstract

To provide an overhead distribution line excellent in strippability, having a stress corrosion disconnection countermeasure effect equal to that of a conventional product and capable of expecting even improvement of arc fusion properties.SOLUTION: An overhead distribution line 1 is formed by arranging a plurality of conductors 3 and 3 in the periphery of a central conductor 2 and covering the periphery of the plurality of conductors 3 and 3 with an insulator 5. The plurality of conductors 3 and 3 have a cross section having an approximately trapezoidal shape and are arranged so that a contact area between adjacent conductors 3 and 3 and a contact area between the plurality of conductors and the insulator 5 become as large as possible; and a watertight agent 4 is charged between the central conductor 2 and the plurality of conductors 3 and 3 and is not charged between the plurality of conductors 3 and 3 and the insulator 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to overhead power distribution lines, and more particularly to overhead power distribution lines having a structure in which a predetermined area inside is filled with a watertight agent.

  There is stress corrosion disconnection as an event that is a problem in the field of overhead distribution lines. The stress corrosion break occurs when rain water intrudes into the inside of the wire and rusting occurs. An overhead distribution line, which has been used conventionally for preventing stress corrosion and breakage, has a structure in which a resin material called a watertight agent is filled in the entire inside of the wire. As an example, there is an overhead power distribution line shown in Patent Document 1 and has a structure shown in FIG. In the overhead distribution line 10 shown in Patent Document 1, a steel wire 11 is disposed at the center, and the steel wire 11 is formed by concentrically arranging a plurality of (six in FIG. 2) conductors 12 and 12 of copper, aluminum or the like. The outer periphery of the plurality of conductors 12, 12 is covered with the insulator 13 to form a wire portion, and the first filler 14 of oil-based watertight compound is filled between the steel wire 11 and the conductors 12, 12. And the second filler 15 made of a water-tight plastic compound is filled in the space between the conductors 12 and 12 and the coating 13 to prevent a reduction in the cross-sectional area of the conductor, and further, to achieve watertightness. It is something that can be improved.

JP-A-11-232934

  However, since the conventional overhead distribution line is filled with the second filler 15 (= watertight agent) between the coating 13 and the conductor 12, it becomes an obstacle and peels off which is necessary for overhead wire construction etc. There is a problem that it is difficult to carry out the operation (removal of the coating).

  Moreover, the moisture which infiltrated in the overhead distribution line 10 permeates toward a center, and there exists a problem that it is easy to corrode between the steel wire 11 and the conductors 12 and 12.

  The inventors of the present invention conducted intensive studies to solve the above problems, and by devising the cross-sectional shape of the plurality of conductors forming the outer core portion, the gap between the plurality of conductors and the insulator or the plurality of conductors In the present invention, it has been found that it is possible to almost eliminate the air gap and prevent the entry of rainwater without filling the watertight agent between the conductors forming the outer core and the insulator. It is the result.

  Therefore, the present invention has good peelability (applicability), has the same effect of preventing stress corrosion breakage as conventional products, and can also expect improvement in arc melting characteristics (easiness of melting by lightning). The purpose is to provide overhead distribution lines.

  In order to solve the above-mentioned subject, the invention according to claim 1 arranges a plurality of conductors around a central conductor, and in the overhead distribution line which covered the circumference of the plurality of conductors with an insulator, the plurality of conductors The cross-sections are substantially trapezoidal, and are arranged such that the contact area with the adjacent conductor and the contact area with the insulator become as large as possible, and the watertight agent is disposed between the central conductor and the plurality of conductors. , And a watertight agent is not filled between the plurality of conductors and the insulator.

  In order to solve the above-mentioned subject, in the overhead distribution line according to claim 1, as for the plurality of conductors, the surface on the insulator side is an arc convex and the center conductor side is It is characterized in that it is an arc concave.

  In order to solve the above-mentioned subject, in the overhead distribution line according to claim 1 or 2, as for the invention according to claim 3, the plurality of conductors are an outer peripheral surface and an inner periphery in the state where a plurality of conductors are twisted together. The surface is arc-shaped in cross section.

  In order to solve the above-mentioned subject, the invention according to claim 4 relates to the overhead distribution line according to any one of claims 1 to 3, wherein the number of the plurality of conductors is 4 to 8. It features.

  In order to solve the above-mentioned subject, in the overhead distribution line according to any one of claims 1 to 4, the invention described in claim 5 is characterized in that the plurality of conductors are compressed under pressure.

  In order to solve the said subject, invention of Claim 6 is an overhead distribution line in any one of Claims 1-5, The said watertight agent is a watertight compound, It is characterized by the above-mentioned.

  In order to solve the above problems, the invention according to claim 7 is characterized in that, in the overhead distribution line according to any one of claims 1 to 5, the watertight agent is a rosin resin.

  According to the overhead distribution line according to the present invention, the contact area between the conductor and the adjacent conductor is maximized as much as possible, and the contact area between the conductor and the insulator is maximized as much as possible. By arranging the body and covering the plurality of conductors and the central conductor with the watertight agent, the space between the plurality of conductors, which is the main rainwater intrusion path, is eliminated as much as possible, and the watertight agent is arranged around the central conductor susceptible to corrosion. In addition to exhibiting a sufficient stress corrosion disconnection countermeasure effect, there is an effect that arc resistance characteristics are improved. In addition, since the watertight agent is not filled between the conductor and the insulator, which are the secondary rainwater penetration paths, there is an effect that the peelability (workability) is improved.

It is a sectional view showing one embodiment of the overhead distribution line concerning the present invention. It is sectional drawing which shows the conventional overhead power distribution line.

[Configuration of overhead distribution line]
Hereinafter, the overhead distribution line according to the present invention will be described in detail based on a preferred embodiment. FIG. 1 is a cross-sectional view showing an embodiment of the overhead distribution line according to the present invention. The overhead distribution line 1 according to the present invention generally includes a central conductor 2 disposed at the center, a plurality of conductors 3 and 3 disposed outside the central conductor 2, a plurality of conductors 3 and 3, and a central conductor 2 And the insulator 5 which coats the periphery of the plurality of conductors 3 and 3. The plurality of conductors 3 and 3 form the outer core portion 6.

  The central conductor 2 is formed of, for example, a metal wire such as aluminum, an aluminum alloy, copper or the like. However, steel wire is used in place of the above-mentioned metal when measures against slackness of overhead wire are required.

  The outer core portion 6 has a structure in which the plurality of conductors 3 (here six pieces) are pressure-compressed in a state in which the watertight agent 4 is filled between the outer core portion 6 and the central conductor 2. The conductor 3 is formed of, for example, aluminum, an aluminum alloy, copper or the like, and the outer core portion 6 is formed by twisting a plurality of conductors. The number of conductors 3 and 4 is 4 to 8 in order to make the outer peripheral surface side (insulation resistant side) and the inner peripheral surface side (central conductor side) in a circular arc shape in a state in which a plurality of conductors are twisted together. It is preferable to have a degree. In addition, the cross section of each of the conductors 3 and 3 has a substantially trapezoidal shape, and the outer peripheral surface side is processed into a circular arc convex surface, and the inner peripheral surface side is processed into a circular arc concave surface, and the conductors 3 and 3 are twisted together In this state, the outer peripheral surface and the inner peripheral surface are circular in cross section. And since the outer core part 6 is formed by compression, adjacent conductors 3 and 3 are surface-contacted and it is formed so that the contact area may become as large as possible. Further, the contact area between the outer peripheral surface of the conductor 3 and the insulator 5 is also made as large as possible. In this case, it is preferable that the contact area between the adjacent conductors 3, 3 and the contact area between the outer peripheral surface of the conductors 3, 3 and the insulator 5 be maximized. By forming in this manner, it is possible to reduce the infiltration of water into the inside of the overhead power distribution line 1 as much as possible.

  The watertight agent 4 has a watertight compound such as EVA (ethylene-vinyl acetate copolymer), EEA (ethylene-ethyl acrylate copolymer), EMA (ethylene-methyl acrylate copolymer), or the like. Resins can be used. Each of the watertight agents 4 may be used alone or in combination. Further, as the watertight agent 4, a rosin resin can also be used. As a rosin resin, rosin ester can be used, for example. Rosin esters are ester resins having adhesive properties derived from the natural resin rosin. Moreover, rosin modified phenol can also be used as rosin resin. The rosin resin can also be used as the watertight agent 4 together with the watertight compound. In the present embodiment, the watertight agent 4 is filled only between the central conductor 2 and the conductors 3 and 3, and the second filler 15 (see FIG. 2) conventionally provided is not necessary. In addition to nothing being filled between the conductors 3 and 3 and the insulator 5, a substance which does not inhibit the releasability between the conductors 3 and 3 and the insulator 5, for example, oil and fat may be filled. As a result, while improving the workability of peeling (coating removal) at the time of overhead wire construction, the presence of the watertight agent 4 makes it possible to obtain the same stress corrosion disconnection countermeasure effect as the conventional overhead power distribution line. Furthermore, by providing the watertight agent 4 which is an insulator, the improvement of the arc fusing characteristic can also be expected.

  As the insulator 5, for example, a vinyl chloride resin or polyethylene, a crosslinked polyethylene or the like is used. In the present embodiment, a pair of fins 7, 7 for snow damage countermeasures are provided, but in applications where it is constructed in an area where there is no snowfall, the overhead distribution lines 1 are not provided with the fins 7, 7. Can be Further, the shape of the fins 7 is not limited to this, and an appropriate shape such as providing unevenness on the entire peripheral surface can be adopted.

[Effect of the embodiment]
According to the overhead distribution line according to the present embodiment, the cross sections of the plurality of conductors 3 are substantially trapezoidal, and the contact area with the adjacent conductors 3 and the contact area with the insulator 5 can be as small as possible. As it is arranged to be large, it is possible to prevent rainwater from entering the inside of the overhead distribution line 1 even if the watertight agent 4 is not filled between it and the insulator 5, and the workability of peeling at the time of overhead wire construction Has the effect of being able to improve In addition, there is an effect that a stress corrosion disconnection countermeasure effect equivalent to that of the conventional overhead distribution line can be obtained.

  Further, according to the overhead distribution line according to the present embodiment, since the watertight compound 4 or the rosin resin is used as the watertight agent 4, the watertight agent 4 functions as an insulator and the arc melting characteristic (melting by lightning Improvement in ease of operation) can be expected.

  Furthermore, according to the overhead distribution line according to the present embodiment, since nothing is filled between the plurality of conductors 3 and 3 and the insulator 5, workability of peeling (cover removal) at the time of overhead wire construction There is an effect that it can be improved.

  As mentioned above, although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the specific embodiments, and within the scope of the present invention described in the claims. It goes without saying that various modifications and changes are possible. For example, although the example applied to overhead power distribution lines is shown in the present embodiment, the present invention is also applicable to other electric wires having a core conductor and an outer core portion composed of a plurality of conductors and having a watertight agent filled therebetween. It is.

1 overhead distribution line 2 central conductor 3 outer core 4 watertight agent 5 insulator 6 conductor 7 fillet

Claims (7)

In an overhead distribution line in which a plurality of conductors are arranged around a central conductor and the periphery of the plurality of conductors is covered with an insulator,
Each of the plurality of conductors has a substantially trapezoidal cross section, and is disposed such that the contact area with the adjacent conductor and the contact area with the insulator are as large as possible.
An overhead distribution line, wherein a watertight agent is filled between the central conductor and the plurality of conductors, and a watertight agent is not filled between the plurality of conductors and the insulator.   The overhead distribution line according to claim 1, wherein the plurality of conductors have an arc-shaped convex surface on the insulator side and an arc-shaped concave surface on the central conductor side.   The overhead distribution line according to claim 1 or 2, wherein the outer peripheral surface and the inner peripheral surface of the plurality of conductors are arc-shaped in cross section in a state in which the plurality of conductors are twisted together.   The overhead distribution line according to any one of claims 1 to 3, wherein the number of the plurality of conductors is four to eight.   The overhead distribution line according to any one of claims 1 to 4, wherein the plurality of conductors are pressurized and compressed.   The overhead distribution line according to any one of claims 1 to 5, wherein the watertight agent is a watertight compound.   The overhead distribution line according to any one of claims 1 to 5, wherein the watertight agent is a rosin resin.

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